1. Field of Invention
The present invention relates to measuring duration times of each of a series of events and particularly to determining the average event duration time.
2. Related Art
Many electronic devices are designed to be used with a variety of systems. For instance, a personal computer add-in card may be used in a "fast computer" or a "slow computer." Because of their use in a variety of systems whose characteristics are often unknown to the electronic device manufacturer, the performance of each electronic device cannot generally be optimized for each system in which the electronic device would possibly be used. Rather, each device is designed with characteristics which are suitable for use in a variety of systems, making performance satisfactory, but not optimal for each system.
Variations in environment not only occur from system to system, but may also occur intrasystem. For instance, when different computer programs are executed, the system loads can vary, causing response time variations within a single system. Thus, even an electronic device designed with certain hardware specifications in mind cannot be optimized by a manufacturer for ideal performance on a system that executes a variety of programs.
If various parameters subject to change are measured in an environment in which an electronic device is placed, the electronic device can be adjusted so that performance of the electronic device is optimized for that environment. Such parameters may include variation in response times or load changes. Moreover, because parameters of interest can vary from instance to instance within a single system, such measurements should be taken over several instances and averaged to find a value that will be most useful in optimizing device performance. However, manual measurement and/or adjustment of these parameters can simply be too burdensome for a typical electronic device user, and, at the very least, extremely inconvenient for either the user or the device installer.
Thus it is desirable to design a device that automatically measures various system parameters, and provides a value that can be used by an electronic device to evaluate system characteristics, enabling the electronic device to adjust itself and optimize performance.
Further, it is desirable to design a device that provides an average value determined over several measured instances. However, averaging circuitry generally requires complicated adding and dividing circuits, often requires significant board space, and can influence other factors as well (e.g., power, etc.). Thus, it is desirable to design a device that determines an average value using minimized, simple circuitry.